Over the past two decades, various digital video compression technologies have been developed and standardized to enable efficient digital video communication, distribution and consumption. Most of the commercially widely deployed standards are developed by ISO/IEC and ITU-T, such as H.261, MPEG-1, MPEG-2 H.263, MPEG-4 (part-2), and H.264/AVC (MPEG-4 part 10 Advance Video Coding). Due to the emergence and maturity of new advanced video compression technologies, a new video coding standard, High Efficiency Video Coding (HEVC), under joint development by ITU-T Video Coding Experts Group (VCEG) and ISO/IEC MPEG. HEVC (ITU-T H.265/ISO/IEC 23008-2) was approved as an international standard in early 2013, and is able to achieve substantially higher coding efficiency than the current state-of-the-art H.264/AVC.
Screen content sharing applications have become more and more popular in recent years with the proliferation of remote desktop, video conferencing and mobile media presentation applications. A two-way screen content sharing system may include a host sub-system including a capturer, encoder and transmitter, and a client sub-system including a receiver, decoder and display (renderer). There are various application requirements from industries for screen content coding (SCC). As compared to natural video content, screen content often contains numerous blocks with several major colors and strong edges because of sharp curves and text that frequently appears in screen content. Although existing video compression methods can be used to encode screen content and then transmit that content to the receiver side, most existing methods does not accommodate the characteristics of screen content and thus lead to a low compression performance. The reconstruction of screen content using conventional video coding technologies often leads to serious quality issues. For example, the curves and texts are blurred and may be difficult to recognize. Therefore, a well-designed screen-content compression method is desirable for effectively reconstructing screen content.